"Project leaders should certainly consider its adoption."
—Linux Weekly News
Every user has access to the full command set, removing boundaries between server and client or committer and non-committers.
Darcs is easy to learn and efficient to use because it asks you questions in response to simple commands, giving you choices in your work flow. You can choose to record one change in a file, while ignoring another. As you update from upstream, you can review each patch name, even the full "diff" for interesting patches.
Originally developed by physicist David Roundy, darcs is based on a unique algebra of patches.
This smartness lets you respond to changing demands in ways that would otherwise not be possible. For example, learn about spontaneous branches with darcs.
First released in 2003, Darcs is now managed by a sizable team of programmers (including David). Daily improvements, combined with tight quality control, culminate in frequent releases.
Binaries and source of the latest stable release of darcs for various platforms including Windows, Mac OS X, FreeBSD and its siblings, Solaris, and AIX, a dozen flavors of Linux, and Cygwin.
While using a binary from above is recommend, here is the latest source code for those who want it.
Darcs source repository
Note, to get the Darcs source you must already have Darcs version 2 or greater (Darcs 1 will give an obscure error). If necessary, download a binary or build the source tarball to get a working Darcs 2.